Ox muscle troponin exhibits significant self-association and polymerization under physiological conditions, which may affect the structural properties of reconstituted actin-tropomyosin-troponin complexes.
May affect reconstituted thin filament models; hypothesis-generating for in vivo troponin behavior with no clinical translation yet.
Ox muscle troponin was shown by equilibrium- and velocity-sedimentation studies to undergo concentration-dependent dissociation into its constituent subunits as well as self-association in imidazole buffers, pH 6.9. The extent of troponin association was found to be strongly dependent on ionic strength and also to exhibit a dependence on pH and temperature; under conditions physiological in regard to pH, temperature and ionic strength the extent of polymerization of troponin is considerable in 2 mg/ml solutions. The ability of polymeric troponin to bind to tropomyosin has been inferred from studies of mixtures containing actin-tropomyosin and an excess of troponin over the amount required for the normal 7:1:1 actin-tropomyosin-troponin complex. These findings should be relevant to studies of reconstituted actin-tropomyosin-troponin preparations, since they signify possible chemical as well as physical differences between the gel, paracrystalline and filamentous states of the complex that result from adoption of different preparative procedures for analogues of the native thin filament.
No takes yet. Share an insight, caveat, or question.
Lovell et al. (1977) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: